1. Field of the Invention
This invention relates generally to an improvement in optic light wave guides and more particularly, but not by way of limitation, to a flexible, inexpensive, efficient optic fiber light guide which utilizes a plurality of flexible unclad optic fibers for improved end to end efficiency.
2. Description of the Prior Art
A need exists for an improved optic light wave guide. Known fiber optic light guides have limited efficiency, that is less than 70%, because of the aperture area that is lost to the protective cladding. Clad solid optic light rods have an improved efficiency but are not flexible and have a limited producible length of less that five meters. Accordingly, the purpose of this invention is to improved the efficiency of a flexible fiber optic light guide in delivered light compared to the light incident on its entrance aperture.
The following patents while of interest in the general field to which the invention pertains, do not disclose the particular aspects of the invention that are of significant interest.
U.S. Pat. No. 4,662,714 issued of May 5, 1987 to Kei Mori discloses a large number of optical conductor cables that are integrated and connected to a single optical conducting rod for use in transmitting light energy through a solid optical conducting rod. The integrated construction comprises a large number of optical conductor cable and a large number of optical fibers, the bundle of which is unbound ate one end of each optical conductor cable. The unbound ends of the optic fibers are then arranged in a common plane and bound to an end of the solid optical conducting rod by a suitable adhesive. The Mori patent does not teach a flexible fiber optic light guide which utilizes a bundle of unclad flexible optic fibers to transmit light while precluding excessive transmission losses.
U.S. Pat. No. 4,697,873 issued on Oct. 6, 1987 to Andre Bouvard et al is directed to a device for optical fibers freed at the end of a cable element. It comprises a sleeve in which the end of a fiber optic cable element is forcibly fitted and a plurality of flexible sheaths are mounted in the line of extension of the sleeve. Each fiber optic of the cable is positioned within and protected by one of such sheaths. Again, there is no showing of a flexible fiber optic light guide which utilizes a bundle of unclad flexible optic fibers to transmit light with improved efficiency.
U.S. Pat. No. 4,666,245 issued May 19, 1987 to John Pointer relates to a fiber optic cable assembly which has three discrete bundles of optic fibers. One bundle is arranged centrally with the other two bundles being shaped in a C-shape and located on opposite sides of the central bundle. A cylindrical ferrule surrounds the end of the cable assembly. The Pointer patent does not teach a flexible fiber optic light guide which utilizes a plurality of unclad optic fibers that trap the maximum amount of light that is being transmitted therethrough.
U.S. Pat. No. 4,483,585 issued on Nov. 20, 1984 to Akiyoshi Takami discloses an illumination device having an optical light guide formed as a fiber bundle. The ends of the fibers fall in a common plane which is positioned against a light guide which is positioned within a ferrule. The Takami patent does not disclose a flexible optic fiber guide which uses a plurality of unclad fiber arranged in a bundle within a suitable protective cladding.
U.S. Pat. No. 4,585,305 issued Apr. 29, 1986 to Elie C. Chazelas II et al discloses a device for arraying the ends of optical fibers disposed around an axially symmetrical structure. The device includes a solid elongate body having first and second opposite end faces between which extend elongated fibers, each groove receives one optic fiber. There is no teaching of a flexible optic fiber light guide which uses a plurality of unclad optic fibers arranged in a bundle with an outer protective cladding.
U.S. Pat. No. 4,576,435 issued on Mar. 18, 1986 to Kimihiko Nishioka relates to light transmitting device that includes a light guide formed by a bundle of optical fibers. Light from a light source is parred through a condenser lens to impinge upon the incident end face of the light guide for transmission to the exiting end face thereof. The Nishioka reference does not teach a flexible fiber optic light guide with improved end to end efficiency that uses a plurality of unclad fibers arranged in a bundle to transmit light.
U.S. Pat. No. 4,141,623 issued Feb. 27, 1979 to Rene Dubost et al discloses a optical fibre cable which includes a central core round which is the optical conductors are concentrically arranged. Each optical conductor is constituted of an optical fiber protected by a first layer of polyamide and a second layer of polyethylene. To avoid distortion of the optical fiber, the second layer is stretched. The Dubost patent does not teach a flexible fiber optic light guide which uses a bundle of flexible unclad optic fibers that are protected by a suitable cladding and which permits crosstalk among the unclad fibers while minimizing transmission loss.